The Royal Navy invented the aircraft carrier and most of the key innovations which have enabled carriers to remain effective, exploiting continuing changes in aircraft technology, from biplanes to supersonic jets. This book tells (and explains) how that happened over more than a century of British carrier development, based largely on declassified official documents, both British and US. Major themes include British domination of the early years of carrier development, and the audacious and highly original plans for their use during World War I, which inspired later naval thinking on the potential of carrier aviation. The introduction of armoured flight decks in the 1930s was only the first of a sequence of British innovations, the most important of which made it possible for carriers to operate jet aircraft (the angled deck, the steam catapult, and the mirror landing sight). These British developments, particularly the steam catapult, were crucial to the survival of the US carrier force in the postwar era, to an extent often forgotten. Later the Royal Navy produced the first commando carriers, and played a crucial role in the VSTOL carrier revolution, and continues to demonstrate originality and innovation as seen in the current pair of large carriers. This book covers all British-built carriers, including those in Commonwealth and foreign service, with the historical context, both operational and technical, explained in detail, as is the connection to larger British national concerns. The book is heavily illustrated with photographs, but also reproduces official plans from the National Maritime Museum, many of which have never previously been published.